Continuous weighing apparatus



Sepa., m9 11934,.

H. HAE-@DANSE v CONTINUOUS WEIGHING APPARATUS 2 sheets-sheet l Filed April 28, 1931 Sept. 11, 1934. H. HARDINGE CONTINUOUS WUIGHING APPARATUS Filed April 28', 1951 2 sheets-sheet 2 Q- A. A. A a N m bw Q 4 .En l

Patented Sept. 1l, 1934 1,973,312 eoN'riNuoUs WEIGHING APPARATUS Harlowe Hardinge, York, lla., assignor to Hah dinge Company, Incorporated, York, Pa., a corporation of Pennsylvania Application April 28, 1931, Serial No. 533,432 ,I

26 Claims.

This invention relates to apparatus for delivering material in a measured quantity and by continuous operation from a hopper to some type of a material receiving apparatus.

Among the objectsoi this invention is to provide a system for controlling the operation of the driving motor for a conveying belt, whereby the motor may be stopped when material is no longer being deposited on the belt, or thev amount of 1 0 material on the belt drops below a desired minimum, and automatically started when a predetermined amount again becomes deposited on the belt. As a part of the system indicating means are provided for informing an attendant (or a central station) that the conveyor and motor are not functioning. A further object of the invention contemplates a motor controlling and signalling system for a plurality of motor driven belts, whereby a drop in the operating condition of one belt will cause the stopping of the motor for driving that belt and the motor of a related conveying belt, and if either or both of two motors is shut down because of a drop in load of Y either or of both belts a signal will be,given.

Other objects contemplate circuits and indicating means whereby different operating conditions of a iiexible belt conveyor may be observed or recorded.

'I'he invention has application to an ordinary conveyor belt of the endless variety type and which passes over a drum at each end.' The drums and belt may be fixed or tiltable as a unit in relation to a hopper and reference will be made hereinafter to both types of conveyors.

The invention has other and' incidental objects in view which consist in certain novel features of construction and combinations oi' parts, the essential elements of which are set forth in the appended-claims and a preferred form of embodi- 40 ment ofwhich is described hereinafter with reference to the drawings. l

In the drawings, Fig. 1 is a side elevation of a conveyor belt unit tiltably mounted in relation to a hopper.

- Fig. 2 is a section on line 2-2 of Fig. 1, showing the position of the circuit controlling device under lo'ad conditions;

Fig. 3 is a section of the apparatus, similar to v Fig. 2, illustrating the positon of the circuit controlling device when the conveyor is not carrying any load;

Fig. 4 is an enlarged view of the circuit controlling device shown in Fig. 2, with the belt-coil tacting roller` shown in section:

Fig. 5y is a section of the' circuit controlling device taken on line 5-5 of Fig. 4;

Fig. 6 is a plan of the circuit controlling device illustrated in Fig. 4;

Fig. '7 is a section on line -'lof Fig. 4;

Fig. 8 is a circuit diagram in which two pairs of contacts and circuits are illustrated,l one for controlling the operation of a motor and the other for controlling an electrical indication or signal.

Fig. 9 is a circuit diagram showing the arrangement for subjecting the operation oi one conveyor to the control of the other conveyor, 'and indicating means for signalling the operating conditions of the two driving motors.

Fig. 10 shows a mercury contacts tube having four pairs of contacts.

Fig. 11 is a side elevation of an endless belt conveyor in which the drums and the belt are fixed in relation to the hopper. l

The apparatus shown in Figs. 1, 2 and 3 comprises a frame and an endless belt which are mounted for pivotal movement as a unit about an axis. The endless belt, which is carried by the frame, is disposed beneath the outlet of a hopper `from which material descends onto one end of the conveyor -or belt. The driving mechanism, which consists of a motor and speed reduction mechanism, is mounted upon the pivoted frame and all of the devices carried by the frame are so related to one another as to maintain the frame in a position of substantial equilibrium about its pivotal axis when material is being measured by the conveyor. The material in the hopper bears upon the endless belt and the quantity of the material leaving the hopper is dependent upon the position of a gate which is mounted upon lever arms having link connection with the frame. The hopper, gate and linkage associating the gate with the frame is such that when the desired amount of weight oi material being measured exceeds a desired weight, the gate will be lowered, and when the delivery of material falls below the desired weight, the gate will be opened; the normal tendency of the apparatus being such that the gate inclines to be maintained in a definite position when the material being weighed does not vary in specific gravity.

In view o f the fact that it is possible to regulate the feed of material according to Weight, several apparatuses may be used to measure different ingredients which are desired to be mixed together, and all ot such apparatuses may be arranged to deliver into a common mixing machine. Owing to lunavoidable circumstances,

such as bin segregation, and variation in the actual weight per unit of volume of a material containing coarse and iine particles, it is desirable that the feeding mechanism be sensitively responsive to weight variation in order that the weight of the material discharged may be determined with exactness. Some materials, such as ores of certain grades and kinds, vary in specie gravity, and it would be wasteful if it should be necessary to segregate the ore before measuring it. In such cases, it is more economical to directly determine the quantity of ore as it is being delivered from a hopper, than to attempt still weighing or sortingfor determination of quantity by summation of weights of segregated volumes of material sorted according to specific gravity.

Having reference to the drawings, frameA 10 is mounted for pivotal movement about bearings 1l which are carried by arms 12, depending from the sides of hopper 13. The conveyor or belt 1i passes over to rollers 15, 16 and is driven in such a manner as to advance the upper span ofthe belt toward the roller 16. The rollers and the conveyor belt are so positioned on the frame 10 as to receive materialirom the hopper 13 in the vicinity of roller 15. The material carried by the belt is delivered from the apparatus as the belt passes over roller 16. The belt may be of any material which is capable of flexing under load and the ordinary commercial types of belts used for conveying material may be used. Leather, rubber or composition and fabric reinforced belts are suitable. Itis a feature of the apparatus of Figs. 1, 2 and 3 that the power means for driving the belt be mounted upon the pivotal frame in order that the balance of the frame and conveyor may not be affected because of the delivery of power thereto from power means located on the ground or from some place other than the pivoted portion of the apparatus. An electric motor is a convenient and compact power means, nonvariable in weight, and I therefore prefer to use such power means for operating the belt. The motor 18 and speed reduction mechanism 19 are mounted upon the frame in such position as to partially compensate for the dead weight of the belt and rollers. A sprocket and chain 20 is used for driving the roller 15 from the speed reduction mechanism.

' The quantity of material delivered from the hopper onto the belt is under the control of a gate 22 which is adapted to move in a vertical direction for varying the height of the heap of material being conveyed thereunder by the moving belt. The movement of the gate 22 is directly associated with the weight of material being conveyed, for when the weightof material being. conveyed exceeds a desired weight for which the apparatus is designed or adjusted to measure, the gate will be caused to descend under the control of the conveyor whose delivery end will have tilted downwardly because of the excess Weight carried thereby; When the weight of material carried by the conveyor falls below -a desired normal delivery weight, the delivery end of the conveyor will rise and thereby cause the gate 22 to rise and permit an increase in the quantity of material to be withdrawn from the hopper by the belt. The gate is moved at a greater rate than the rate of rise or fall of the belt below the gate and this results in a rec'urring effort to maintain a constant rate 0i' delivery of material. y

The gate 22 is carried by arms 23, one on each side of the hopper, and these arms are mounted for pivotal movement about shaft 24. One of arms 23 extends beyond shaft 24 and forms another arm 25, which is connected to frame 10 by means of a link 26 pivoted at its ends to arm 25 and frame 10. lIt is this mechanism which causes the gate 22 to be lowered when the delivery end of the conveyor lowers and vice versa, for the reasons above set forth.

In order to eirect an adjustment of the apparatusl for delivering a desired weight of material per unit of time, a weight 27 is provided, which is slidably mounted upon an extension of one arm 23. By a certain setting of the weight, the apparatus will'continuously deliver a constant weight of material and will automatically maintain the delivery constant until readjustment of the apparatus is made.

When several apparatuses of this kind are bein used to measure and maintain the weights of materials subsequently to be mixed, it is important that an operator be immediately advised if one or more oi the apparatuses should cease to deliver material. Even when only one apparatus is beng utilized it is always desirable that the operator know if it is operating without performing any work. If no material is being delivered from the hopper to the conveyor, it is wasteful to permit the conveyor to be driven, and its revolution counter will give a false reading. In order to apprise the operator of the operation of any particular apparatus and the character of the material being measured, I have provided circuit means suitable for giving necessary indications to inform the operator. I have disclosed forms of such means as being illustrative of the application of'my invention. In Figs. 4 and8, particularly, the circuit controlling means comprises a contacts carrying member 30, which is pivotally mounted to tip about pin 3l, which is supported in a fixed position by means of a member 32. 'I'he normal position of member 32 is illustrated in Fig. 3.

Ail

Referring` to Figs. 4 and 5, member 32 is 120 mounted upon the upper end of a screw 33, which, in turn, is supported by a bracket 34 fastened -to a bar 35 extending across the frame and between the upper span and the lower span of the belt 14. The bar 35 is carried by arms 36 which have their upper ends permanently fastened to the frame 10. The contacts carrying member 30 has mounted thereon a belt-engaging element, preferably in the form of a roller which is so positioned below the upper span of the belt as to be contacted by the same when the belt is carrying material. For this purposea roller 40 may be placed in a position similar to that illustrated in Figs. 2 and 3, or it may be placedplaterally of that position, but in most cases it is preferable to place the contacting element or roller nearer the center line of the belt than its edge. roller 40 may be bevelled to a more or less degree as at 41, in order that the Wear upon the belt may be maintained at a minimum. Screw 33 provides the means for varying the height of the roller in respect to the bracket 34 and the frame 10, and, when a desired adjusted position is obtained, the nut 42 is screwed home so as to lock the screw in a desired position.

In general, when the apparatus is adjusted and delivering a constant Weight of material per unit of time, the position of the roller should be such as to engage the upper span of the deected belt. Such a relation is illustrated in Fig.

The'

vso

2. When the belt is without load or with light load, the upper span of the belt is not deflected suniciently to engage and tip the roller, see Fig. 3. The belts which are used are sufliciently hexible to deiiect when loaded. The contacts carry ing member 30 is so mounted upon pin 3l that it will tip to the position illustrated in Fig. 3 unless pressure is brought to bear upon the roller 40. The limits of swinging movement of the member about the pin 31 are determined by adjustment screws 43, 44, mounted in oppositely disposed arms 45, 46, respectively, which depend from member 32. The ends of the screws are so positioned as to engage an arm 47 which is carried by the contacts carrying member 30. As illustrated in Figs. 4 and '7, the position of the arm i7 is midway between the ends of screws 43, de. In

Fig. 2, the arm 4'? maintains the contacts carry-a ing device in the position illustrated by virtue of its engagement with the end of screw 43, and in lug. 3 the engagement of arm e7 with screw e4 serves to prevent pivotal movement of the contacts carrying member 30. For the purposes oi the disclosure of the invention, I have described what is my preferred form oi device for mounting the roller ec, but it is to be understood that the specific construction descri'bed is merely illustrative and that other forms oi device for mounting the belt engaging element and contacts carrying member may be utilized for practicing the invention.

For the purpose of simplifying the disclosure or" my inventon, l.' have illustrated. the circuit conm trolling device as a glass tube 50 Figs. 2, 5, fi, 5 and 8 containing mercury and as having but two pairs oi contacts 51, 52 in liig. 8. In order to i`a-u cilitate positioning of the glass tube 50 on the con= tacts carrying member 30. pairs oi spring mein--` bers 53 are provided. ln the wiring diagram oi Fig. 8, one terminal 53 is connected with a inotor 5i which is connected to one side of battery 55. Terminal 56 is connected with the other side of the battery. When the contacts carrying niernn ber 30 and the tube 5o are 'tilted to the position shown in Fig. 2, terminals 53 and 55 will be closed by the mercury contained within the glass tube. When no load or a light load is being carried by the belt, the contacts carrying member '30 and the tube 50 will be tilted into the position illusm trated in Fig. 3, with the result that terminals 59 and 6c will. be closed by the mercury 58 contained within tube 5G. rIihe closing oi these terminals causes current to Flow from battery 55 'through lead 6l, terminal 59, mercury 58, terminalcb, inw` dicator 62, lead 53, baclr to battery'55, thus cans ing an indication to be given by the indicator 52. This indicator may be in the forni of an audible signal such as a bell, or may even be used to oper` ate the printing oi a time indication upon a clockcontrolled tape. 4

ln Fig. 9, I have shown a wiring diagram showing how the contacts tubes i'or two conveyors may be placed in circuit so that if either (or both) of the two motors is shut or the other motor is shut ofi and an indication is given by signalling means. Brieiiy, contacts 65, 65 are in series and motors 67, 68 are in parallel with the source oi" power 69. lf tube 'T10 is tilted, contacts 55 are opened and the motors receiveno current, also contacts ll close and current flows through contacts 65, contacts "Jl (or`72), line "13, indicator '74, to the source of power 69.

The features of the invention so far described are also applicable to measuring apparatus having a conveying belt which is not mounted upon l a frame tiltable as a unit in respect to the hopper. In Fig. ll I have diagrammatically shown such a conveying belt 76 as mounted upon two drums 77 and 78 whose axes of rotation are nxed in relation to a hopper 79. Just below or in the vicinity of the outlet of the hopper, a contacts carrying member similar to the one illustrated in Figs. i, 5, 6 and 'l is mounted. With the con tacts carrying member so placed and in contact with the under side of the upper span of the belt, different quantities of material on the .belt under different operating conditions will cause different degrees of deflection of the belt and of the mem ber. As a means of obtaining various indications of different operating conditions of the apparatus, I contemplate the use of a multi-contact signal-= ling system, which will afford the means of indi eating more than two different conditions.

The mercury tube having double sets oi contacts, as illustrated in Figs. 2 and 3, t, 5, and 5, is suitable for controlling the operation ci the motor and for giving an indication of the fact that the operation oi" the motor has been .discontinued. For controlling circuits operating means for indicating diuerent degrees of loading, a number o similar contacts tubes may be used, or a single tubemay be used similar to the tube ilu lustrated in Fig. lo. .'lhis tube is curved and is provided with. several pairs oi contacts. '.lhis tube could be carried on a mounting similar to that provided ior the contacts carrying member 3o. its various contacts would be closed, depend ing upon the position of the mercury within the tube and the angular position oi the tube. in a multi-contact tube, for examplaiour sets of con tacts might be provided. Contacts 5l could serve to maintain the motor in operation and to give an indication, ii desired, that the apparatus is operating under'norrnal conditions. Contacts 52 lilrewise would maintain the motor in operation and give an indication Vthat the apparatus is measuring a quantity of material in excess of the normal weight of material desired to be delivered per unit of time. Contacts 53, would maintain the motor in operation and give an indication that the apparatus is performing under a lighter load than normal. Contact 8d would be connected' to an indicator to advise the operator that the motor had ceased operation.

lt is apparent iroin the foregoing that one opernl ator may watch the performance ci severai dit ierent apparatuses, operating independently ci each other or as a group oi related apparatuses and always be informed oi the operating condi-D tion of any particular apparatus, whether in a group or not, as well as the condition of operam tion of the various groups of apparatuses. @ne operator may supervise the operation or several groups oi measuring apparatuses and may also obtain a record of the performance oi any one apparatus. When several apparatuses are being used to measure the quantities oi different in= gredients entering into a mix, a variation from normal operation oi any one apparatus would causethe giving or" a signal to indicate that the prevailing condition should be remedied.

i claim:

i. In combination, a continuous weighingapf paratus comprising a frame pivotally mounted on a horizontal axis, an endless conveyor carried by said frame and tiltable with said frame and operable to convey material in a direction lateral to the pivotal axis of said frame, means for indicating the loaded condition of said con-1 veyor, said means comprising a contacts-carry tilt?) litt) lill@ ling member carried by saidA frame and pivotally mounted thereon to respond to loaded conditions ol said conveyor, the contacts of said member being closable when said member is pivoted to a predetermined position, an indicating device, and circuit means rendered operative upon the closlng of said contacts for operating said indicating device.

2. In combination, a continuous weighing apparatus, comprising a frame pivotally mounted on a horizontal axis, an endless conveyor carried by said frame and tiltable with said frame, means for indicating the loaded condition of said conveyor, said means comprising a contacts-carrying member pivotally supported below the upper span' of said conveyor, a roller carried by said member and adapted to be engaged by the upper span of said belt when carrying material, circuit means for indicating the loaded condition of said conveyor, and contacts for said circuit means carried by said member for closing various circuits of said'circuit means.

v3. The combination set forth in claim 2 in which the contacts are adapted to be closed by the .position of mercury within a tube. f

i- 4. In combination, acontinuous weighing apparatus comprising a frame pivotally mounted ona horizontal axis, a conveyor including a belt and rollers carried by said frame and tiltable with said frame, a motor foroperating said conveyor, and means for indicating the loaded condition of-said conveyor, said means comprising an indicating device and circuits to said indicating device and said motor, and a tube containing contacts adapted to be closed by mercury for selectively closing said circuits.

f :5. In combination, a continuous weighing apparatus comprising a frame pivotally mounted on aA horizontal axis, a conveyorincluding a belt carried by said frame and tiltable with said frame, said conveyorgbeing operable to pivot 'about the axis of said frame, a member carried by said frame and pivotally mounted thereon to re`- j spond to loaded conditions of said conveyor, and

' circuit means including a multi-contact mercuryvcontaining tube for selectively controlling the circuits in accordance with various weights of material on said conveyor, at least one of said circuits being operative to control the operation c f the conveyor.

` 6. Incombination, -a continuous weighing apparatus comprising a frame pivotally mounted on a horizontal axis, a belt carried by said frame 'and tiltable with said frame, ra contacts-carrying member pivotally supported below the upper span' 'of said belt, said member being adapted to be engaged by the upper span of saidbelt when carrying material,v a motor for driving said belt, circuit means including contactscarried by said member for controlling the operation of said motor.-

- 17.111 combination, a continuous weighing apparatus comprising' a frame pivotally mounted on a' horizontal axis, a belt carried'by said frame and tiltablewith said frame and operable vto convey material in a direction lateral to the pivotal axis of said frame, means for indicating the loaded condition of said belt, a member carried by 'said frame and pivotally mounted thereon to respond to loaded conditions of said belt, contacts closable when said member is pivoted to a predetermined position by contact With said belt, circuit means rendered operative upon the closing of said contacts for operating said indicating means. and a motor for actuating said belt invasie under the control of at least one of said circuits, said motor circuit being opened upon a decrease in load uponthe belt below a predetermined minimum load.

8. In combination, a continuous weighing apparatus comprising a frame pivotally mounted on a horizontal axis, a traveling belt carried by said frame and tiltable with said frame, said belt being operable to convey material in a direction lateral to the pivotal axis of said frame, a hopper containing material disposed adjacent one end of said belt, means for indicating the loaded conditions of said conveyor, said means comprising a member carried by said frame and pivotally mounted thereon to respond to loaded conditions of said belt, said member being disposed underneath the upper span of said belt and in the vicinity of the hopper feeding material onto the belt, whereby said member may be actuated as the belt yields to the pressure of the material upon it, contacts carried by said member for closing `indicating circuits, and indicating circuits adapted to indicate the tilted relation of said member in response to the loaded conditions of said belt.

9. In combination, a continuous weighing apparatus comprising a frame pivotally mounted on a horizontal axis, a traveling belt carried by said framev and tiltable with said frame, said belt being operable to convey material in a direction lateral to the pivotal axis of said frame, a hopper containing material disposed adjacent one end of said conveyor, a member carried by said .frame and pivotally mounted thereon to respond to loaded conditions of said belt, said member being adapted to be actuated by the material within the hopper and upon the belt as the belt yields to the pressure of the material upon it, contacts carried by said member for closing a circuit, and indicating means for indicating the loaded condition of said belt.

10. In combination, a continuous weighing apparatus comprising a frame pivotally mounted on a horizontal axis, a traveling belt carried by said frame and tiltable with said frame, said belt being operable to convey material in a direction lateral to the pivotal axis of said frame,

a member operable by the deflection of said belt under load, circuit means controlled by said member and means for indicating the loaded condition of said belt under the control of said circuit means.

-11. In combination, a continuous weighing apparatus comprising a frame pivotally mounted on a horizontal axis, a belt and rollers carried by said frame and tiltable with said frame, said belt being operable to convey material in a direction lateral to the pivotal axis of said fran-1e, a member adjustable in position by the deection of said belt, a motor for actuating said belt and circuits under the control of said belt for controlling the operation of said motor.

12. In combination, a continuous Weighing apparatus comprising a frame pivotally mounted on ahorizontal axis, belt and rollers for actuating the same, mounted on lsaid frame, and tiltable therewith, saidl belt being operable to convey material in a direction lateral to the pivotal .axis of said frame, means for indicating the iso Leraars f means for adjusting the operating position oi said member in respect to said frame.

13. In combination, a continuous weighing apparatus comprising a frame pivotally mounted on a horizontal axis, a belt and rollers for actuating the same, mounted on said frame, and tiltable therewith, said belt being operable to convey material in a direction lateral to the pivotal axis of said frame, means for indicating the loaded conditions o said belt, said means comprising circuits and a contacts-carrying member carried by said frame and pivotally mounted thereon and adapted to be contacted by said belt when said belt is loaded with material, and means for adjusting the range of the angle oi tilt of said member.

14. In combination, a continuous weighing apparatus comprising a belt, a motor for driving said belt, means for indicating dierent loaded conditions of said conveyor, said means comprising an indicating device, circuits to said indicating device and circuits to said motor, and a tube containing contacts adapted to be closed by mercury for selectively closing said circuits.

15. In combination, a continuous weighing apparatus comprising an endless conveyor, means for indicating the different loaded conditions of said conveyor, said means comprising a member pivotally mounted to respond to loaded conditions of said conveyor, pairs of contacts closable when said member is pivoted to diderent predetermined positions by the deiiection of said belt, and circuit means rendered operative upon the closing of said contacts.

16. In combination, a continuous weighing apparatus comprising an endless conveyor, means for indicating different loaded conditions of said conveyor, said means comprising a contactsn carrying member pivotally supported below the upper span of said conveyor, a roller carried by said member and adapted to be engaged by the upper span of said belt when carrying ma" terial, circuit means for indicating the loaded conditions of said conveyor, and pairs of contacts for said circuit means carried by said mem ber for closing various circuits oi said circuit means.

1'?. In combination, a continuous weighing apparatus comprising a belt, an electric motor for operating said belt, a member pivotally mounted to respond to loaded conditions of said belt, and circuit means including a multncontact niercury-containing tube for selectively controlling the circuits in accordance with various weights oi' material on said belt, at least one of said circuits being operative to control the operation of the motor.

13. In combination, a continuous weighing ap paratus comprising a belt, a motor for driving said belt, a hopper having at least a portion thereof above an unsupported portion oi? the upper span of said belt, contacts means con" trolled by the deflection of said belt, and circuit means under the control oi.' said oontactsmeans ior shutting down the motor whenthe load on said beit falls below a predetermined minimum.

19. In combination, a continuous weighing ap=l paratus comprising a belt, a motor for driving said belt, a hopper having at least a portion thereof above an unsupported portion ci' the upper span or said belt, a contacts-carrying mem=n ber pivotally mounted belowsaid upper span and in the vicinity of said hopper, said member being in contact with said belt, and circuit means operable to shut off the motor when the load on said belt drops to a predetermined minimum and operable to give a signal when the motor is shut oir, said circuit means being under the control of said contacts-carrying member.

20. In combination, a continuous weighing apparatus comprising a belt, a member adjustable in position by the deflection of said belt, a motor for actuating said belt, and circuits under the control of said belt for controlling the operation of said motor.

2l. In combination, a continuous weighing apparatus comprising a belt, a hopper, means for indicating the loaded conditions of said belt, said means comprising circuits and a contacts-carrying member carried by said frame and pivotally mounted thereon and adapted to be contacted by said belt when said belt is loaded with material, and means for adjusting the operating position of said member in respect to said hopper.

22. In combination, a continuous Weighing apparatus comprising a belt, a hopper, means for indicating the loaded conditions of said belt, said means comprising circuits and a pivotally mounted contacts-carrying member adapted to be contacted by said belt when said belt is loaded with material, and meansfor adjusting the range of the angle of tilt of said member.

23. In combination, a continuous weighing apparatus comprising a belt, a contacts-carrying member pivotally supported below the upper span of said belt, said member being adapted to be engaged by the upper span of said belt when carrying material, a motor for driving said belt, circuit means including contacts carried by said member for controlling the operation ci said motor.

2t. In combination, a plurality of continuous Weighing devices, each comprising a traveling belt and a motor for driving the belt, contactscarrying means responsive to the deflection of the belt and circuit means under the control oi said contacts carrying means for shutting down the driving -motors or all of said belts unfl derthe control or the contacts means of any one of said belts.

25. In a device of the class described, the combination with a frame mounted on ahorizontal axis, or a conveyor including a belt, rollers, and a motor carried by said frame and tiltable with said frame, an indicating device, circuits to said indicating device and said motor, and a contacts-carrying member carried by said 4frame and tiltable independently oi said frame for selecm 'tively closing said c'ncuits. n

26. In a device o the class described, the coml bination with a frame liti mounted on a horizontal airis, ci a conveyor including a belt carried by said iframe and tiltable with said frame, a memm ber carried by said iframe and pivotally mounted thereon to respond to loaded conditions of said conveyor, indicating means, and circuit means including a mercury containing tube carried by said member ior actuating said indicating means iu accordance with various weights of material on said conveyor.

HARLGWE HARDINGE. 

